This invention relates generally to combustion devices and, more particularly, to a method and apparatus for controlling combustion dynamics developed within combustion devices.
Gas turbine engines typically include a compressor section, a combustor section, and at least one turbine section. The compressor compresses air, which is mixed with fuel and channeled to the combustor. The mixture is then ignited to generate hot combustion gases. The combustion gases are channeled to the turbine which extracts energy from the combustion gases for powering the compressor, as well as producing useful work to power a load, such as to propel an aircraft in flight.
Gas turbine engines operate in many different operating conditions, and combustor performance facilitates engine operation over a wide range of engine operating conditions. Controlling combustor performance improves overall gas turbine engine operations. For example, at least some gas turbine low NOX emissions combustion systems employ a process known as lean premixed combustion wherein fuel and combustion air are mixed upstream of the combustion zone to facilitate controlling NOX production. Such systems often function well over a relatively narrow operating range. Outside of the range, combustion dynamics levels (noise due to oscillatory combustion process) may approach an amplitude that can shorten the maintenance intervals and/or ultimately cause component damage and failure.